Aeroplane



Jan. 30, 1934. c. c. BVITTNER 1,945,254

AEROPLANE Filed Nog. 2, 1951 5 Meets-Sheet 1 Jan. 30, 1934. c. c. BITTNER 1,945,254

AEROPLANE Filed Nov. 2, 1931 3 Sheets-Sheet 2 c. c. BITTNER Jan. 3o, 1934.

AEROPLANE Filed NOV. 2, 1931 3 Sheets-Sheet 3 Patented Jan. 30, 1934 UNITED STATESv PATEN T OFFICE,

12I Claims.

The invention relates to aeroplanes.

The object of the invention is to providean aeroplane provided with wings which can be operated to provide, when required in navigation, lateral, longitudinal and vertical stabilities to prevent spinning or auto-rotation, nose diving, and side slipping.

Another object of the invention is to provide means for automatically shifting the wings to prevent loss of control of the plane when it stalls in flight or the speed is reduced below a kpredetermined rate. f f

A further object of the invention is to provide an aeroplane which is adapted to land ina restricted area.

Other objects of the' invention and the various advantages and characteristics of'the present laeroplane construction will be apparent from a consideration of the following detailed description. f

The invention consists. in the several novel features which are hereinafter set forth and are more particularly defined by claims at the conclusion hereof.

In the drawings which accpmpanynd form a part of this specification or disclosure and in which like numerals of reference denote corresponding parts throughout the several views: Fig. 1 is a plan of an aeroplane embodying the invention. Fig. 2 is a front view. Fig. 3 is a detail side elevation. Fig. 4 is a plan, showing n the hinged connections between the wings and the fixed section of the supportingA structure. Fig. 4a is a detail plan of one of the hinges of said connections. Fig. 4b is an end view of the hinge shown in Fig. 4. Fig. 5 is a plan of one of the ailerons. Fig. 5B is a vertical section through one of the ailerons when it is in normal l position. Fig. 5b is a section through the aileron Cil of Fig. 5a when it has been swung upwardly. Fig. 5c is a similar section showing the aileron swung downwardly. Fig. 6 is a: diagrammatic view of the mechanism for controlling, the setting of the wings. Fig. 'l is a vertical section showing one of the connections for shifting the wings. Fig. 8 is a front elevation of said connection.

The invention is exemplified .in an aeroplane comprising a fuselage 20, a motor 21, a propeller 22 driven by the motor, and a cock-pit `23 for the pilot, all of which may be offany suitable or vwell known construction or design. yA counterbalanced elevator l1 is mounted at the-tail of the fuselage and its side portions are sloped upwardly to dispense with the'use of stabilizers. A counter-balanced rudder 19 is also provided at the tail of the fuselage and may be controlled by any ysuitable means, as well understood in the art. n y n The Wing structure comprises acentral section 24L which is rigid with the fuselage or body and is generally in the form of an isosceles triangle having its base at the rear or trailing edge. In addition to the central section 24, the wing structure comprises a pair of wings 25 which wings 25 extend laterally from and are pivoted to the sides respectively of the xed section 24. The inner ends of the wings 25 are inclined rearwardly correspondingly to the sides of section 24 and are pivoted to swing upwardly and rearwardly on axes at the meeting-edges of the section 24 and the inner side margins of the wings 25. The axes of these pivots diverge rearwardly from a point lat the front edge of the wings to their rear edges and extend approximately at angles of 20 from the transverse center of the wing structure.

Normally, the wings and xed section are substantially coplanar and are properly inclined with respect to the longitudinal axis of the aeroplane for the desired angle of incidence at flying speed. The axes of these pivots are in a plane substantially parallel with the plane of the wings. The rearwardydivergence of the axes of these pivots causes the wings, when raised, to swing upwardly and rearwardly into oblique positions, as shown by dotted lines in Figs. 1, 2 and 3. 'Ihis setting of the wings increases the angle of incidence and positions the wings so they will be upwardly divergent and inclined rearwardly. When the wings are thus set, the lateral stability is increased by the increased dihedral position of the wings; and the center of gravity of the aeroplane is lowered relatively to the point of lift to counteract'auto-rotation and is moved forwardly to give greater longitudinal and vertical stability to the plane and prevent nose diving. The in-` crease 4in the angle of incidence of the wings increases the lift. This change in thesetting of the wings therefore results inv an increase of lateral, longitudinal, 'and vertical stability which substantially eliminates the spin, side slip, and nose dive, and makesl it. possible to gain altitude at a steeper rate of climb whenrising, and to land in a short space and at a slow speed. By means of the automatic setting of the wings hereinafter pointed out, the aeroplane will `be rendered safe in operation and have a great factor of safety whenever the speed of the'plane Ifalls below -normal flying speed. By K eliminating spin, nose dive, and side-slipping, as aforesaid, the plane can be safely landed whenit goes into ya stall without the likelihood of a'spin orsideslip. When the wings are set in their raised' position, their' action resembles that of aparachute when speed is reduced or the motor fails thus'making itlpossible to drop substantially vertically and safely, without nose-diving or spinning.v

The pivotal connectionsbetween each r25 27 which are secured to the beams 28 which constitute support for the wing, hinge-members 29 on a frame 30 in the rigid wing-section 24, and pivotbolts 31 which extend obliquely through the hinge members and are coaxial. Each hinge is covered by a leather cover 32 to close the air gap over it. Two overlapping metallic resilient strips 33 close the gap below the hinge.

The mechanism for controlling the swinging movements of each of the wings, comprises a cylinder 34 and a piston 35 adapted to be operated by air under pressure. The lower end of each cylinder 34 is held by a ball and socket joint comprising a ball 36 and a spherical socket 37 which is iixedly connected to a rigid support 38 which forms part of the landing-gear for the fuselage. A tubular strut or stem 40 is fixed to piston 35 and slides through a packing box 41 in the upper head of the cylinder 34. A bifurcated fitting 42 is adjustably connected by a screw-threaded connection to the tubular strut 40 and a lock-nut 43 is adapted to lock the bracket and stem in assigned relation. The lower end of this fitting is split so it can be clamped on the stem by the nut. Fitting 42 is pivoted, at 44, to a bracket 45. A pin 46 extends through the upper end of fitting 42 and a curved slot 47 in bracket 45, to keep the fitting in alignment with the bracket 45. Bracket 45 has its upper end hinged by pins 48 to hinge-members 49 which are secured to the wing-beams 28. These connections permit of universal movement of the cylinder and piston, in order that the operating connections for the wing are free to swing the wing from its lowered to its raised position. 'Ihese connections form universal joints between the cylinder and the support 38 and between the piston and the wing and constitute a supporting strut for the wing. The adjustment between the fitting 42 and the piston-stem 35 permits the extreme angle of the wing to be varied as desired. The axis of the cylinder and piston connection is inclined upwardly and rearwardly from the point of connection to the frame 38 in order eiciently to support the wing. Washers 54 of cork or rubber or other suitable compressible material in the ends of the cylinder 34 act as bumpers for cushioning the movements of the piston in the cylinder at the ends of its stroke.

The cylinder and piston connections between the landing gear and the wings are preferably `of such character that when the wings are swung upwardly to their fullest extent the dihedral of each wing is increased 20 (see dotted line position of wings in Figure 2). In practice it has been found that by increasing the dihedral to this extent, maximum lateral stability is 0btained. By virtue of the fact that the wings are pivoted on rearwardly divergent axes which ex' tend approximately at 20 angles with respect to the transverse center line of the wing structure, the angle of sweep back is increased approximately 1%" and the angle of incidence is increased approximately 7 when the wings are swung upwardly into their safety position, that is, in the position wherein the dihedral angle is increased approximately 20. By increasing the angles of sweep back and incidence to this extent, maximum counteraction of auto-rotation is obtained.

A steel cable 55 is attached to a` rod 56 which is mounted in the wing-beams 28 and extends downwardly alongside of the cylinder 34 and around a pulley 58 and then around a take-'up pulley 59. A tension spring 60 is applied to pulley 59. The lower end of cable 55 is suitably secured in the fuselage. An indicator 61, usually mounted on the dashboard in the cockpit, is operatively connected to the pulley 59 to indicate the movement and position of the wings while the plane is in` operation.

The operation of the pistons 35 to lower and raise the two wings is controlled by air under pressure adapted to enter and escape from the upper ends of the cylinders 34 through fittings 50 which are connected to the upper end of pipes 51 respectively, and flexible pipes 52 which are connected to the lower ends of pipes 51.

A tank 62 contains a supply of compressed air and is connected by a pipe 64, a flexible section 65 and a fitting 66 to deliver air to one side of a valve-casing 53. A valve 67 in casing 53 is adapted to control the delivery of compressed air to the cylinders 34 to operate the pistons 35 to lower the wings. Valve-casing 53 is mounted on a lever (control-stick) 68 which is pivotally supported at 69 and is the pilots instrumentality for controlling the aeroplane. The stem of valve 67 is connected to a button 70 in the upper end of lever 68, so that by depressing the button 70 the pilot can operate the valve 67 to admit air to the cylinders 34 to control the lowering of the wings. A valve 71, also mounted in casing 53, is adapted to control the exhaust of air from the upper ends of cylinders 34 through pipes 51, so that when the aeroplane is in fiight, the wings will be released and lifted automatically in response to the pressure exerted by the air beneath the wings. A hand-lever 72 is pivoted on one side of the lever 68 and is connected by a rod 73 to operate the valve 7l. Casing 53 is connected by the pipe 52 to the casing of a valve 85, to which are connected the pipes 51 leading to both cylinders 34. This exemplifies manually controlled means for controlling the setting of the wings.

The tank 62 is kept charged with air from one of the engine cylinders by an accumulator valve 74, which causes pressure from the enginecylinder to pass through a. cooling coil 75 and then through a filter 76 from which the air under pressure passes into the tank 62. A pres sure indicator 62 is provided in the cock-pit so the pilot can observe the pressure in tank 62.

The setting of the wings, besides being under the manual control of the pilot, is automatically controlled for emergencies when the pilot becomes incapacitated or fails to act, by means of a Pitot tube 77 mounted in advance of the leading edge of one of the wings. As the aeroplane gets near the minimum cruising or stalling speed, a signal light 79e is actuated. This signal light 79n is mounted on the usual speed indicator 79 controlled by the Pitot tube 77. If the condition of the aeroplane is not detected by the pilot in due time and the speed of the plane continues to diminish, then the speed indicator 79 will cause a valve 85a in casing 85 to be operated to release the pressure of the cylinders 34. For this purpose indicator 79 is l 55 When in night, either through stalling or other switch 86 is included in the circuits 80 and 83 which are connected to battery 87 to control manually said circuits. This exemplifies mechanism for automatically controlling the setting of the wings responsivelyto the slowing up of the plane so that the wings will be lifted to shift them upwardly and rearwardly to give them a greater angle of incidence and to give the aeroplane greater lateral, longitudinal and vertical stability and to prevent the tail spin, side-slip and' nose diving.

Ailerons are pivotally connected to the wings and are disposed at the outer rear corners thereof, Each aileron is provided with a longitudinally extending slot or opening 16. This opening terminates in the front of the aileron so it will be closed when the aileron is in its normal position and in its lowered position. This slot is curved to scoop the stream flow below the wing when the aileron is lifted and the front end of the slot is brought below the lower wing surface and into the stream flow. The slot extends from the front of the aileron backwardly and upwardly to the top face of the rear portion of the aileron. When the aileron is lifted, as shown in Fig.

5b, its front edge will pick up the streamflow at.

the bottom of the wing and discharge it at the top of the aileron to render the aileron more' effective and counteract the drag of both ailerons. The inner end of each aileron shaft 16n (Fig. 4) is connected by a universal joint 16C, which is coaxial with one of the ,wing-hinges, to a shaft section 16d which is mounted in bearing 16e on the rigid section 24 of the wing structure. Any suitable connections may be employed for operating the shafts 16a by the control lever 68. The universal joint 16c maintains the connection between shaft-section 16d and shaft 16EL in the different angular settings of the wing. Wing overlaps 25 extend shortly below the wings from the leading edge of the wings to the trailing -edge of the ailerons.

The operation of the aeroplane will be as follows:

Intaking off ,the pilot will depress the button 70 to operate valve 67 to deliver air under pressure from tank 62 into the upper ends of the cylinders 34. This air under pressure will operate the pistons 35 downwardly in the cylinders and swing the wings downwardly to their normal or transversely coplanar position. The air pressure will be kept in the cylinders 34 during normal flying conditions. During normal flight, the wings will remain in their lowered or normal position to enable the plane to travel at its maximum speed.

causes, the wings begin to lose their lifting force, the center of gravity ofthe plane changes, and the aeroplane loses its stability. After the maximum angle of incidence has been reached, any further increase of the angle of. attack develops a nose heavy moment andV lacking the necessary lateral and longitudinal stability, auto-rotation moments or spinning sets in. Under any of these abnormal conditions, the pilot will shift the khand-lever 72 to operate the valve 'Il to release the air pressure in the cylinders 34 so that the air pressure against the underside of the wings will lift them to their raised position. When thus shifted, the wing-setting will be upwardly and rearwardly divergent, and the pressure against them will be counteracting. 'This will prevent spinning or auto-rotation, and an unequal drag on either of the main air foils. The sweep-back and increased angle of incidence, to-

gether with the counteracting forces on the` wings, will cause the plane to right itself or maintain its proper position, and eliminate the spin, side-slip and nose dive. In event the plane slackens near the' minimum cruising or stalling speed and the pilot fails to operate the vmanual control to set the wings in their safety position, the valve which is controlled by the speed indicator 79, will be automatically .operated to release the air from the upper ends`of the cylinders 34 so that the wings will be set to their angular or safety position independently of the pilot. In landing the pilot can also set the wings in their raised position to increase the angle of incidence, and sweepback, so they will actsimilarly to a parachute in preventing the plane from entering a sideslip, spin or nose dive, and to cause the plane to make a landing in a cornpar'atively short distance.

The invention is not to be understood as restricted to the details set forth, since these may be modified within the scope of the appended claims, without departing from the `spirit'and scope of the invention.

Having thus described the invention, what I claim as new and desire to secure by Letters Patent, is: v

l. In an aeroplane, the combination of a fuselage, wings pivoted to swing dihedrally and vertically on rearwardly divergent axes, and means controlled by the speed of travel for retaining the wings in different positions.

2. In an aeroplane, the combination of a motorpropelled fuselage, a pair of wings projecting outwardly from the fuselage sides and pivoted on rearwardly divergent axes'and adjacent said fuselage to swingfupwardly and rearwardly from a normal flying position into a predetermined safety position wherein the dihedral and angles of sweep-back and incidence of the wings are increased to conteract auto-rotation. means for holding the wings in their normal flying position, and means for releasing the holding means so the wings are free to swing upwardly and rearwardly into their safety position in response to the air pressure exerted on the under faces of the wings.

3. In an aeroplane, the combination of a motor-propelled fuselage having a cock-pit therein, a pair of wings projectingY outwardly from the fuselage sides and pivoted on rearwardly divergent axes and adjacent said fuselage to swing upwardly and rearwardly from anormal flying position into a predetermined safety position wherein the dihedral and angles of sweepback and incidence of the wings are increased to counteract auto-rotation, means for yieldingly holding the wings in their normal flying position, and means controlled from the cock-pit for releasing the holdingmeans so the wings are free to swing upwardly and rearwardly into their safety position in response to the air'pressure exerted on the under faces of the wings.

4. In an aeroplane, the combination of a .niotor-propelled fuselage, a pair of wings projecting outwardly from the fuselage sides and pivoted on rearwardly divergent axes and adjacent said fuselage to swing upwardly and rearwardly from a normal flying position into a predetermined safety position wherein the dihedral and angles of sweep-back and incidence of the wings are increased to counteract auto-rotation, means for holding the wings in.their normalflying posi- 5. In an aeroplane, the combination of a motor-propelled fuselage, a pair of wings projecting outwardly from the fuselage sides and pivoted on rearwardly divergent axes and adjacent said fuselage to swing upwardly and rearwardly from a normal flying position into a predetermined safety position wherein the dihedral and angles of sweep-back and incidence of the wings are increased to counteract auto-rotation, means operable .by fluid under pressure for yieldingly holding the wings in their normal flying position, and means for controlling the fluid so as to render the holding means inoperative and free the Wings so that they are caused during flight to swing upwardly and rearwardly into their safety position in response to the fluid pressure exerted on the under faces of the wings.

6. In an aeroplane, the combination of a motor-propelled fuselage, a pair of wings projecting outwardly from the fuselage sides and pivoted on rearwardly divergent axes and adjacent said fuselage to swing upwardly and rearwardly from anormal ying position into a predetermined safety position wherein the dihedral and angles of sweep-back and incidence of the wings are increased to counteract auto-rotation, struts for supporting the wings having pistons attached thereto, cylinders wherein the pistons are slidable, means for supplying fluid under pressure to the cylinders to cause-the pistons to move in a direction wherein they operateto swing the wings into their normal flying position, and means for cutting off the supply of fluid under pressure to the cylinders and releasing the fluid in said cylinders in order to release the pistons so that they are free to shift in the opposite direction and the Wings are free to swing upwardly and outwardly into their safety position in response to the fluid pressure exerted on the under faces of the wings.

7. In an aeroplane, the combination of a motor-propelled fuselage having a cock-pit thereiny a pair of wings projecting outwardly from the fuselage sides and pivoted on rearwardly divergent axes'and adjacent said fuselage to swing upwardly and rearwardly from a normal flying position into a predetermined safety position wherein the dihedral and angles oi.' sweep-back and incidence of the wings are increased to counteract auto-rotation, struts for supporting the wings having pistons attached thereto, cylinders wherein the pistons are slidable, means controlled from the cock-pit for supplying air under pressure to the cylinders to cause the pistons to move in a direction wherein they operate to swing the wings into their normal flying position, and means also controlled from the cock-pit for cutting oil the supply of air to the cylinders and releasing the air in the cylinders in order to release the pistons so that they are free to shift in the opposite direction and the wings are free to swing upwardly and outwardly into their safety position in response to the air pressure exerted on the under faces of the wings.

8. In an aeroplane, the combination of a motor-propelled fuselage having a cock-pit therein and a control-stick in the cock-pit, a. pair of /wings projecting outwardly from the fuselage sides and pivoted on rearwardly divergent axes and adjacent said fuselage-to swing upwardly and rearwardlyfrom a normal flying position into a predetermined safety position wherein the dihedral and angles of sweep-back and incidence of the wings are increased to counteract autorotation, and means lfor controlling swinging of the wings into and out of their safety position comprising a control-element mounted on the Y stick in the cock-pit. '.80

9. In an aeroplane, the combination of a motor-propelled fuselage, a pair of wings projecting outwardly from the fuselagesides and pivoted on rearwardly divergent axes which extend at approximately 20 angles with respect to the transverse center line f the wing structure and permit the wings to swing upwardly and rearwardly from a substantially coplanar normal flying position, means for preventing the wings from swinging upwardly and rearwardly beyond a safety position wherein the dihedral angle is substantially 20, and means for controlling swinging of the wings from their normal flying position to their safety position.

10. In an aeroplane, the combination of a motor-propelled fuselage, a pair of wings projecting outwardly from the fuselage sides and pivoted on rearwardly divergent axes which extend at no greater than 20 angles with respect to the transverse center line of the wing structure and permit the wings vto swingupwardly and rearwardly from a substantially, coplanar normal flying position, means Afor preventing the wings from swinging upwardly and rearwardly beyond a safe- .ty position wherein the dihedral angle of the wings is substantially equal to the pivot angle of each Wing, and means for controlling swinging` of the wings from their normal flying position to their safety position.

11. In an aeroplane, the combination of a ino- 110 tor-propelled fuselage, a wing structure comprisf ing a xed wing section in the form of an isosceles triangle and with substantially straight side margins which diverge rearwardly, a pair of end wing sections extending outwardly from the fixed wingvsection and having the inner ends thereof angled correspondingly to the side margins of the fixed wing section and pivoted to said margins so that the end wing sections'may be swung upwardly and rearwardly from anormal flying position wherein they are substantially coplanar, means for preventing the end wing sections from swinging upwardly and rearwardly beyond a safety position wherein the dihedral angle is the same as the angle at which each side margin of the xed wing section extends with respect to the transverse center line of the wing structure, and means for controlling upward swinging of the end wing section from said normal iiying position to their aforesaid safety position.

12. In an aeroplane, the combination of a motor-propelled fuselage, a pair of wings projecting outwardly from the fuselage and pivoted on rearwardly divergent axes which extend at no greater than 20 angles with respect to the transverse 135 center line of the wing structure to permit the wings to swing upwardly and rearwardly from a substantially coplanar normal ying position, means for preventing the wings from swinging upwardly and rearwardly beyond a safety position wherein the dihedral angle does not exceed 20 and the angles of sweep-back and incidence are increased to the proper degree for effective counteraction of auto-rotation, and means for controlling swinging of the wings from their normal flying position to their safety position.

' CHARLES C. BITINER. 

